Today there is a massive quantity of high-level nuclear waste accumulating across the world. In the U.S. alone there are more than 70,000 metric tons (MT) of high-level solid nuclear waste (HLW) being stored in cooling pools and in concrete casks on the Earth's (land's) surface. Such surface operations are very costly typically costing hundreds of millions of dollars annually. The HLW is generally called spent nuclear fuel (SNF) and consists of thousands of nuclear fuel assemblies which have been removed from nuclear power plants. There is a significant need for new processes to safely eliminate and/or greatly reduce the surface storage of this radioactive waste and to sequester this SNF waste in a safe manner for very long times at least more than 10,000 years. In this patent application HLW and SNF are used interchangeably to describe the solid nuclear waste product which is radioactive.
Nature has already developed a “safety deposit box” for high level nuclear waste. This “box” is the deep buried stable plutons, multi-million year old, basement rock intrusions into the near surface crust of the earth. This patent application illustrates, describes, and discloses methods, systems, and mechanisms that can access and utilize these natural “boxes” for disposal and storage of high level nuclear waste.
In this patent application the words pluton, craton and basement rock are used interchangeably and refer to the specific deep formation rock into which the repository for the nuclear waste may be implemented. In addition, the term site and location are used interchangeably in this patent application may generally refer to a land's surface location/site for receiving a drilling a rig and subsequent placement and drilling operations.
This patent application illustrates an internment process in deep basement rock structures. These basement rock structures are called cratons and plutons. Basement rock is the thick foundation of ancient, and oldest metamorphic and igneous rock that forms the crust of continents, often in the form of granite.
The term craton distinguishes the stable portion of the continental crust from regions that are more geologically active and unstable. Cratons can be synonymous with shields, described as the basement rock which crops out at the surface. Cratons may also be known as platforms, in which case the basement rock is overlain by sediments and sedimentary rock which are usually less dense and softer than the basement rock. A pluton may be an intrusive body of igneous rock that is crystallized from magma slowly cooling below the surface of the Earth. There may be different types of plutons, such as, batholiths, stocks, dikes, sills, laccoliths and other igneous formations.
To date (circa 2017), and based on the prior art, in order to provide satisfactory and economical final disposal of radioactive nuclear wastes, it is desirable that the radioactive nuclear wastes be sequestered in a system where it is isolated from the biosphere.
Based on the notable and inherent shortcomings of the prior art, e.g., costs, complexity, lack of public acceptance, environmental shortcomings, there exists a critical need for an effective, economical method for developing and utilizing deep geologic repositories. It is generally accepted by most nuclear and scientific experts that deep geologic burial is the best solution for long-term nuclear waste disposal.
The prior art contemplates drilling vertical wellbores directly into cratons from the land's surface. This subject invention illustrated herein, may initially use substantially vertical wells which may be drilled outside and relatively adjacent (proximate) to a given craton (or basement rock structure) to a predetermined vertical depth, and then by turning the drill bit to the substantially horizontal, continue drilling at least one lateral well which may continue substantially horizontally into the craton (or basement rock structure) body itself.
An objective of this invention may be to provide a deep geologic repository that is deep enough, drillable, capable, economic, and to maximize the benefits of basement rock disposal (storage) at the lowest possible cost without compromising safety and security.
To solve the above-described problems, the present invention may provide systems and methods to implement disposal of radioactive nuclear waste currently accumulating on the Earth's (land's) surface by optimally siting these deep geologic repositories by a combination of analytical methods, mechanical and physical processes to provide the best feasible working solution.
A novel approach as taught in this patent application may provide methods and systems wherein the radioactive nuclear waste disposal operations may be optimized from a site selection perspective.
Throughout this patent application the terms craton, pluton, and basement rock are used interchangeably and describe the specific basement rock structures which are very stable and usually igneous or metamorphic in nature or origin. These basement rock structures may be harder and/or more dense than sedimentary rock.
It is to these ends that the present invention has been developed.